Baij Lambert, Hermans Joen J, Keune Katrien, Iedema Piet
Van't Hoff Institute for Molecular Sciences, University of Amsterdam, P.O. Box 94720, 1090GD, Amsterdam, The Netherlands.
Rijksmuseum Amsterdam, Conservation and Restoration, P.O. Box 74888, 1070DN, Amsterdam, The Netherlands.
Angew Chem Int Ed Engl. 2018 Jun 18;57(25):7351-7354. doi: 10.1002/anie.201712751. Epub 2018 Mar 9.
The formation of metal soaps (metal complexes of saturated fatty acids) is a serious problem affecting the appearance and structural integrity of many oil paintings. Tailored model systems for aged oil paint and time-dependent attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy were used to study the diffusion of palmitic acid and subsequent metal soap crystallization. The simultaneous presence of free saturated fatty acids and polymer-bound metal carboxylates leads to rapid metal soap crystallization, following a complex mechanism that involves both acid and metal diffusion. Solvent flow, water, and pigments all enhance metal soap crystallization in the model systems. These results contribute to the development of paint cleaning strategies, a better understanding of oil paint degradation, and highlight the potential of time-dependent ATR-FTIR spectroscopy for studying dynamic processes in polymer films.
金属皂（饱和脂肪酸的金属络合物）的形成是一个严重问题，影响着许多油画的外观和结构完整性。针对老化油画的定制模型系统以及随时间变化的衰减全反射傅里叶变换红外光谱（ATR-FTIR）被用于研究棕榈酸的扩散及随后的金属皂结晶过程。游离饱和脂肪酸和聚合物结合的金属羧酸盐同时存在会导致金属皂快速结晶，其遵循一个涉及酸和金属扩散的复杂机制。溶剂流动、水和颜料都会增强模型系统中的金属皂结晶。这些结果有助于制定油漆清洁策略，更好地理解油画的降解过程，并突出了随时间变化的ATR-FTIR光谱在研究聚合物薄膜动态过程方面的潜力。
